An emergency official says human error is to blame for a tornado alert mistakenly sent to about 500 people in the Charlottesville-Albemarle County area.

Residents received phone calls and text messages about the alert Wednesday morning. They subsequently were notified by text messages and email that the warning was sent in error.

Tom Hanson is executive director of the Charlottesville-University of Virginia-Albemarle County emergency communications center. He tells The Daily Progress that an activate button for a preloaded notification message was inadvertently pressed during training for the local emergency alert system.